Analyses of varve thickness time-series data: A climate link

Conference · Mon Mar 01 04:00:00 EST 1993 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5688438

Roach, D E; Fowler, A D; Burbidge, G ^[1]

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1. Univ. of Ottawa, Ontario (Canada). Ottawa Carleton Geoscience Centre and the Dept. of Geology

Varves are sand-clay sedimentary couplets deposited annually in glacial lakes. Previous work has shown that the Fourier spectra of the individual bed thicknesses are intractable, or at least require significant filtering prior to analysis. This is, in part, because the data are not strictly periodic but are quasiperiodic. Therefore, a natural approach to their analysis is the use of techniques of non-linear dynamics. Varve sequences are too short (typically n[approximately]100) to allow time series analyses using the correlation function. The authors show results obtained using a predictor technique for many sets of unfiltered varve-data ranging in age form Quaternary to Precambrian. These are interpreted to show deterministic control of sedimentation, beyond the obvious annual cycle. In contrast, rhythmic sediments from very different environments (e.g. turbidites) show no deterministic signal. A series composed of scaled Quaternary varve data combined with scaled Quaternary tree-ring data also shows a strong deterministic signal. These data are consistent with the postulated existence of a climate attractor.

• OSTI ID: 5688438
• Report Number(s): CONF-9303211--
• Conference Information: Journal Name: Geological Society of America, Abstracts with Programs; (United States) Journal Volume: 25:2
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
AGE ESTIMATION
DATA ANALYSIS
DEPOSITION
GEOLOGIC DEPOSITS
GEOLOGY
GLACIERS
LAKES
PALEOCLIMATOLOGY
PALEONTOLOGY
SEASONAL VARIATIONS
SEDIMENTS
STRATIFICATION
STRATIGRAPHY
SURFACE WATERS
VARIATIONS